You should actually check whether the movement is in the automatic GM list. If it's not there, it means that the system is not even trying to post it.
Bear in mind that only components are backflushed. The finished product is automatically Goods received and it's driven by different settings. Could it be that you have a serial number profile on the finished good? If this is the case you can't post automatic goods receipt and the the flag in the operation is ignored.

GIUSEPPE CASCELLI

Help the community by fixing grammatical or spelling errors, summarizing or clarifying the solution, and adding supporting information or resources. Always respect the original author.

It should have actually worked, but it might be that the system couldn't post the 101 due to some errors. Have you checked transaction COGI if it's there?
In any case, if the movement is automatic, you should see it in the "goods movements" button that you have in CO11n (or CO15) when you processed the confirmation. Have you seen it? If it's there but wasn't posted, I'm 100% sure that it went into COGI. Otherwise there should be something else in the process.

With autoGR option, you have to define goods receiving storage location/production storage location in production order/material master/production version. It is mandatory with autoGR option, otherwise it will go to COGI. Please check COGI for any other error.

I'd check the production order header, control tab to make sure the production scheduling profile you expect to see is assigned. This functionality works for the last confirmable operation, make sure that is the one that is confirmed in your order.

Sometimes AGRs and backflushes can go to CO1P instead of COGI. This can happen if settings have been made in OPKC to update in background and I've seen it happen if confirmations are done via Bapi. There may be other reasons also, anyway check out CO1P.

Hi B,
We are thinking of creating a process key that does the auto GR and
backflushing immediately in update program, then specify the new process
key in the appropriate order type for the plant. This is because we are
using Bapi and many GM are going to CO1P. I have no experience using
"immediately in update program" so can you give me some pointers, or
potential issues to watch for. Any help would be greatly appreciated.

You should actually check whether the movement is in the automatic GM list. If it's not there, it means that the system is not even trying to post it.
Bear in mind that only components are backflushed. The finished product is automatically Goods received and it's driven by different settings. Could it be that you have a serial number profile on the finished good? If this is the case you can't post automatic goods receipt and the the flag in the operation is ignored.